Heat exchange apparatus



H. H. DOW

Feb. 23, 1932.

HEAT EXCHANGE APPARATUS 2 Sheets-Sheet Filed Aug. 26, 1926 A INVENTOR.,J/erberz J1. 170W BY 6 M a @944 ATTORNEY.

Fb. 23, 1932. H, D W 1,846,955

HEAT EXCHANGE APPARATUS Fil-ed Aug. 26, 1926 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY HERBERT ly where there Patented Feb. 23, 1932' UNITED Ji STA EsATENT;- oFFIca PAITY, OF MIDLAND, MICHIGAN, A CORPORATION OF MIGHIGANHEAT APPARATUS Application filed Au ust 28, 1926. Serial 1rd. 131,798.

This invention relates to systems involving a step of heat exchange, andmore particularis considerable difference 10 pressure between the fluidsconcerned or where there is possible danger if interleakage shouldoccur. It is among the objects of the invention to provide such systems,a safeguard in these contingencies. objects and advantages will appearas the description proceedsi Tovthe accomplishment of the foregoing andrelated ends, the invention, then, consists in the features'hereinafterfully described, and particularly pointed out in the claims, thefollowing description and the annexed drawings setting forth but few ofvarious forms in which the may be employed.

Insaid annexed drawings Fig. 1 is a schematic view in section of anembodiment of my invention; and Fig. 2 is a similar view of amodification.

In its general aspects, my invention contemplates a system including ameans for containing a hot fluid, and a meanslfor containing a fluid tobe heated, there being an" intermediary fluid for transferring heatfromthe one to the other.

In Fig. 1 reference'numeral 1 designates a container for the fluid to beheated. De-

pending upon the particular application of the invention, this willvary, but for example may be! a boiler for containing water to beheated. An outer-set ofpartitions or tube sheets 2, 3, and an inner setof partitions or tube sheets 4, 5,'are arranged in the container 1, andtubes 6 extend between theinner tube sheets 4, 5, while smallertubes 7extend be. tween the outer tube sheets 2, 3, and lie within the tubes 6.There is thus, provided a compartment A having-a well or larger channel8 arranged as desired, and a series of tubes 7 connecting the respectiveportions of the compartment, while an inner. compartment B is formed inrelation to the compartment A and having a connection 9 as an=inletfor ahot fluid andv an outlet 10. Between. these respective compartments Aand B, there is thus a third. general compartment C, this comprising thespace between the partitions having Other.

principle of the invention I 2 and 4 and the tubes 6 and 7 and thepartitlons 3 and 5. Preferably I connect this ."general compartment Cwith. anexpansion chamber or standpipe l1, and to accelerate .thecirculation, it is desirable to include a pump 12 in the circuit betweenthe chamber 11' and the compartment C.

With a fluid such as water in the chamber A, and a fluidin the chamber Bto give up heat to such water, it will thus be seen'that the respectivefluids are separated by the intermediary compartment C which, is provided with a heat-transfer fluid of suitable character. Desirably thisheat-transfer fluid is maintained in active circulation, preferably suchas to involve turbulence; In this manner a more effective transfer isrealized. If now, the difference of pressure between the fluid inchamber A and the fluid in chamber B be considerable, there will be atendency toward leakage through joints, and if the pressure in chamber Cbe sufliciently lower than that in chamber A such leakage will be seento occur from chamber A into the intermediary fluid in chamber C. Thisinter: 'mediary not only allows of a. stepping down various chambers, i.e.,-from a working pres-' sure inchamber A to lower pressures inchambers B and C, although the pressure of fluid in chamber 0 may be atapproximately a. DOW, or unite in), MICH GAN, asslenon' ro ran nowGHEIHGAL oonrof pressure gradient of the fluids in the 7 that of thefluid in chamber B or higher than I such pressure, but in the case ofsuchv fluids as on mixing would start detrimental action, I am thusenabled to interpose an eflective barrier by virtue of such intermediaryfluid in the chamber C. For instance, .if thefluid'in compartment A bewater and. the fluid in compartment'B were aluminum bromide to becondensed from vaporous state, the tem- .perature of such bromideunder'a pressure of one atmosphere is above 506 F. while water in thecompartment A at a temperature raised say to 486 F. would represent apres-- sure of about 600 pounds'absolute, thus involving a difierentialwhich would be ex tremely diflicult tohold even by the best possibleseams, and any leakage of water into the aluminum bromide compartmentwould result in the formation of hydrobromic acid in relation to a shellwith partitions or tube sheets 27, 28. Tubes- 29 extend between thesetube sheets and a with disastrous results. The intermediary compartmentC in such case would thus fur-- nish an additional'set of barrier Wallsand a. corresponding stepping down of the abrupt pressure gradient, andat the same time by proper selection of the intermediary. fluid in thecompar'tmentC, all danger of disastrous interaction in case of leakagewill be'avoided. Carrying the foregoin illustration further, if theintermediary fluid be for instance diphenyl oxide, its boiling point .ata pressure of one atmosphere is about 496 F., thus giving anintermediary which allows of ready heat-transfer from the aluminumbromide to the water compartment, and any leakage from the watercompartment under its relatively high pressure would occur into thediphenyl oxide with harmless results. By

adding a-condenser system including a condenser 13 having suitablecooling means, and a drawofl' pipe 14 to a separator .15, any leakageoccurring from the water compartment A into 0 would be in state ofvaporand would pass oil from the top or vapor space 16 of the receptacle 11along with any diphenyl oxide vapor to the condenser 13 where both wouldbe condensed and flow'down to the separator 15. In this the water wouldstratify above the di henyl oxide condensate and would flow 0E diphenyloxide would return by pipe 17 and trap 18 to receptacle 11. a

In the form shown in Fig. 2, instead of including the heating fluidchamber'B within the walls of the container 1, it is located outside. 'Aset of partitions or tube sheets 19, 20, is provided. and tubes 21extend therebetween, there being also if desired a well 22. The chamberA thus has tubes joining its different portions, and immediatelysurrounding the tubes is an intermediate chamber C. Baflles 23 may bearranged in this compartment to provide a more eflicient distribution ofthe fluid therein. Connecting with the compartment C is an inlet 24 andan outlet 25 26 which is provided partition 30 may be arranged in theheader space sons to more eflectively divert the-fluid to flow throughthe tubes. Between the partitions or tube sheets 27, 28, there is thusformed a general compartment B having an inlet connection 31 and anoutlet connection 32. In this arrangement a hot fluid for instanceispassed in from any source through connection 31, and circulates aboutthe tubes 29 to the outlet connection 32, giving up heat h inits passageto the fluid inside of the tubes, if

this being circulated, preferably actively by pump 33 so as to passaround through the compartment'C in the container 1 and there by give upheat to the fluid in compartment An expansion tank or standpipe 34 isdesirably arranged in relation with the comthrough the overflow 16,\while the b .ed therewith providin partment C, and a condenser systemincludthis makes possible the handlin of chemical substances eitherin'the sense 0 cooling and condensing on the one hand, or heating andcompartment and intermediary heat-tran er fluid 1s vided between themain fluids concerned, and

vaporizing on the other, without detrimental 5 effects from leakag..Moreover, a power plant utilizing the properties-of high boilv ingliquids may be arranged on this order,

for instance a high boiling point substance such as aluminum bromide canbe used as a primary power-vapor giving up its energy'to a turbine orthe like, to its boiler through a heat exchange relationship with waterin erate steam which may be used as a secon ary power-fluid in acorresponding unit, and with the intermediary heat-transfer fluid ascontemplated by this invention, the large pressure difl'erential can bereadily handled without dangers which would otherwisebe' inherent inattempt at conjoint use of such agents.

This invention will thus be seen to be capale of application withvarious substances a water boiler to en and in various relationships,where an intermediary heat transfer agent can be employed to eliminatedangers otherwise inherent.

Other modes of applyin the principle of the invention may be ing made asregardsthe features disclosed,

emp oyed, change beprovided the means or steps set forth in any. of thefollowing claims, or the equivalent of such, be employed,

I therefore particularly point out-and distinctl' claim'as my inventioni.

1. n apparatus of the character described, the combination of acontainer for a fluid to be heated, outer and innersets of tube sheetstherein, tubes extending between the inner tube sheets, smaller tubespositioned within said tubes and extending between the outer tubesheets, an external container in communication with the tubes whichextend between the inner tube sheets, and a pump for circulatin a fluidthrough said-external container and communicating tubes.

2. In apparatus of the character described,

the combination of a container for a fluid to be heated, a double set ofpartitions associate ing fluid and a charm r intermediate for aeat-transfer'fluid, and means for separating rom such heat-transferfluid leakage-contaminations of other fluid.

3. In apparatus of the character described, the combination of acontainer for a fluid to be heated, a container for a heating fluid,anintermediate container in heat exchange relation with both theaforesaid for containing a chamber for a heat: 4

a heat-transfer -fluid, a pump for circulating such fluid through saidintermediate container, a Vapor off-take from the top of saidintermediate container, a condenser for said vapor 5 ofi-take, aseparator for condensate, and a,

connection from the separator to said intermediate container. v

Signed by me this 20th day of August, 1926. 10 HERBERT H. DOW.

